Process of making a coal-tar product



UNITED STATES PATENT OFFICE.

JOHN H. WEISS, 01' NEW YORK, N. Y., ABSIGNOB TO THE BARRETT COMPANY, A CORPORATION OF NEW JERSEY.

PROCESS OF MAKING- A COAL-TAR PRODUCT.

No Drawing.

To all tvkomitma concem.

Be it known t at I, Jomw M. Wnrss, a citizen of the United States residing at 210 West 110th street, New York city in the county of New York and State of ew York, have invented certain new and useful Improvements in Processes of Making a Coal-Tar Product, of which the following is a specification.

This invention relates to the production or isolation of certain constituents'of tars,

such as coal tar, water gas tar, oil gas tar, blast furnace tar, etc. t relates more particularly to the process of separatin such of these constituents as are insolu le in petroleum naphtha from the other constituents, and also to the product thereby obtained.

It is well known that such tars consist of alarge number of compounds of difierent characteristics, a large portion of which can be removed by distillation. The residue left after distilling is commonly known as pitch.

The melting point of this residue or pitch depends upon the extent to which the distillation has been carried and the commercial product varies from about 100 F. to 300 F., or higher. The original tars as well as the pitches derived therefrom contain a certain amount of so-called free carbon which can be removed by adding a solvent such for example as benzol, to the tar or pitch, which solvent does not dissolve the free carbon, and then filtering the solution, after which the benzol may be evaporated from the filtrate to leave the bituminous material which then contains substana sufiicient amount of t e petroleum naphtha to dissolve the constituents of the bitumen that are soluble in. the petroleum naphtha. The residue is then separated from the Specification of Letters Patent.

Application flied October 2?, ma Serial 110. $33,401.

petroleum naphtha solution in any conven ient manner as by filtration, and constitutes the product that is insoluble in petroleum naphtha. If the free carbon has not been removed from the bitumen before the-petroleum naphtha extraction it may be removed as above indicated after the constit ants insoluble in petroleum naphtha have een isolated. 3

Tar bitumens of the character indicated ranging from liquid tar to the hardest grades of itch may be treated in accordance with this invention to obtain a bitumen that is insoluble in petroleum naphtha and such roduct may be made containing free caron, or ma be made free fromit according to the esires of the user. The melting point of the substance thuspbtained does not depend entirel bitumen from whic it was obtained, and in all cases will be a hard, brittle bitumen of high melting point. The substances thus obtained, when free of the so-called free The substances thus obtained are espe cially useful for lining or coating the inside of tanks or receptacles that are to contain petroleum products because they are insoluble in or practically unaffected by such products even after long exposure to the action of the same. If necessary, these substances may be fluxed with non-volatile materials that are more nearly liquid than these substances, and are themselves insoluble in petroleum naphtha, for the urpose of producing a mixture that is so er and can be more easily handled and applied than the hard bitumen. The substance or such fluxed material may, however, be dissolved in any suitable solvent such, for example, as coal tar naphtha, and a plied in situ as a layer or film after whic the solvent is permitted to evaporate.

These bituminous substances which are insoluble in petroleum naphtha find a wide variety of uses in places where resistance to petroleum roducts is an important consideration. or example, the maybe used as binders for mastics which ave to resist the action of petroleum products. These substances possess hi h electrical insulating properties and may e used to cover the surace of electrical conductors that are subjected tothe influence of petroleum products, or fabrics may be saturated with solutions of these substances without decreasing their insulating qualities, but actually increasing the same, while at the same time rendering them resistant to the action of gases or fumes or other products of petroeum.

Claims:

1. The herein described process which com rises treating the coal tar naphtha soluble constituents of tar bitumen with petroleum naphtha and separating the soluble portion from the insoluble residue.

2. The herein described process which com rises treating the coal tar naphtha solu le constituents of coal tar bitumen with petroleum naphtha and separating the soluble portion from the insoluble residue.

3. Tue herein described process which comprises extracting some of the coal tar naphtha soluble constituents of tar bitumen by means of petroleum naphtha, thereby leaving a residue substantially insoluble in said naphtha.

4. The herein described process which com rises treating the coal tar naphtha solu le constituents of pitch derived from tar with petroleum naphtha and separating the soluble portion from the insoluble residue.

5. The herein described process which comprises treating the coal tar naphtha soluble constituents of coal tar pitch with petroleum naphtha and separating the soluble portion from the insoluble residue.

6. The herein described process which comprises treating coal tar bitumen with a solvent derived from coal tar filtering, removing the solvent from the filtrate b distillation and extracting from the distil ation residue such constituents as are soluble in petroleum naphtha.

7. The herein described process which comprises treating tar bitumen with benzol, filtering, distilling the benzol from the filtrate, and extracting from the distillation residue the constituents that are soluble in petroleum naphtha.

8. The herein described process which r comprises treating pitch derived from tar with benzol, filtering, distilling the benzol from the filtrate, and extracting from the distillation residue the constituents that are soluble in petroleum naphtha.

In testimony whereof I aflix my signature.

JOHN M. WEISS. 

